In the ICN world there are multiple factors that contribute to challenges in evolving robust subscriber authentication schemes for services. These include architectural variations (centralized or de-centralized or hybrid, request-response, publish-subscribe and so on) which enable different mechanisms by which subscribers can retrieve content of their interest, trust levels between entities participating in an ICN network resulting in challenges related to assigning authentication or authorization responsibilities, availability of in-network caching, multipath, multicast delivery, packet level authentication and other network centric capabilities to optimize secure content delivery and finally evolving service sets i.e. the types of novel services that can be enabled in an ICN era is constantly evolving. Each of the above factors impacts how subscriber may be authenticated and gives rise to different threat models to be addressed by the possible solutions. Presently, there exists no formal mechanism to analyze a given ICN service and clearly elicit the requirements for authenticating subscribers for the service. This also creates challenges when it comes to verifying whether a given authentication solution meets all the requirements specific to the service.